A teacher at a Welsh high school was kicked off the flight taking children to the United States - despite holding a valid visa.
Teacher Juhel Miah had flown to Reykjavik in Iceland from Britain with the schoolchildren before boarding a flight to New York.
But before the plane took off on February 16, Mr Miah was escorted off the flight by security.
The school trip from Llangatwg Comprehensive in Aberdulais in Neath Port Talbot continued as planned - but the teacher's removal left pupils and colleagues "shocked and distressed."
Educations chiefs in Neath Port Talbot County Borough Council has now written to the Embassy of the United States of America in London to express its dismay at the treatment of Mr Miah.
The teacher from 700-pupil Llangatwg Comprehensive has been described as a "popular and respected teacher".
We are appalled by the treatment of Mr Miah and are demanding an explanation. The matter has also been raised with our local Member of Parliament.
The school party returned to Britain today after their week-long trip to New York via Iceland.
The reason for the US refusing entry to Mr Miah was unclear to school leaders.
President Donald Trump issued a controversial travel ban earlier this month, banning travel to the US from seven mainly-Muslim countries.
The Supreme Court temporarily suspended the move, however the President has since issued a revised immigration ban targeting the same seven countries listed in his original executive order.
While the draft order is still subject to change, it could be signed off as early as this week.